Liquid-liquid contactor employing pulsed plates having holes of different size in each plate

ABSTRACT

AN APPARATUS FOR CONTACTING TWO FLUID PHASES. IN A VERTICAL VESSEL ADAPTED FOR THE SUPPLY AND THE DISCHARGE OF FLUIDS THERE ARE AT LEAST TWO PLATES ONE ABOVE THE OTHER ADAPTED TO BE MOVED RECIPROCATINGLY IN THE DIRECTION OF THE LONGITUDINAL AXIS OF THE VESSEL. THE PLATES ARE PROVIDED WITH TWO TYPES OF HOLES DIFFERING IN SIZE AND MAY ALSO DIFFER IN SHAPE. THE AREA OF THE SMALLEST HOLES OF THE LARGER TYPE IS AT LEAST THREE TIMES LARGER THAN THE AREA OF THE LARGEST HOLES OF THE SMALLER TYPE. THE NUMBER OF HOLES OF THE SMALLER TYPE IS AT LEAST 65% OF THE TOTAL NUMBER OF HOLES IN A PLATE. THE POSITION OF HOLES IN ADJACENT PLATE ARE DIFFERENT. THE PLATES MAY BE PROVIDED ON ONE SIDE WITH AN ADJUSTABLE OR STATIONARY BAFFLE.

June 8, 19"'11 J. LANDAU ETAI- LIQUID-LIQUID CONTACTOR EMPLOYING PULSED PLATES HAVING HOLES 0F DIFFERENT SIZE IN EACH PLATE 4 Sheets-Sheet. 1

Filed May 28, 196s June 8, 1971 J. LANDAU Erm.

LIQUID-LIQUID CONTACTOR EMPLOYING PULSED PLATES HAVING HOLES OF DIFFERENT SIZE IN EACH PLATE 4 sheets-sheet 2 Filed May 28. 1968 BY /lc/LLL) June 8, 1971 J. LANDAU ETAL 3,583,856 LIQUID-LIQUID CONTACTOR EMPLOYING PULSED PLATES HAVING HOLES OF DIFFERENT SIZE IN EACH PLATE 4 Sheets-Sheet 5 Filled M8128. 1968 FIB. lr

FIG. 5

Jllne 8, 1971 J, LANDAU ErAL 3,583,856

- LIQUID-LIQUID CONTACTQR EMPLOYING PULSED PLATES HAVING HOLES 0E DIFFERENT SIZE IN EACH PLATE Fild may 28A 1968 4 Sheets-5h96?. 4

United States Patent O 3,583,856 LIQUID-LIQUID 'CONTACTOR EMPLOYING PULSED PLATES HAVING HOLES OF DIF- FERENT SIZE IN EACH PLATE Josef Landau, Ladislav Prochzka, and Frantiek Souhrada, Prague, Czechoslovakia, assignors to Ceskoslovenska akademie ved, Prague, Czechoslovakia Filed May 28, 1968, Ser. No. 732,699 Claims priority, application Czechoslovakia, .lune 13, 1967, 4,339/67 Int. Cl. B01d 11/04 U.S. Cl. 23-267 11 Claims ABSTRACT OF THE DISCLOSURE An apparatus for contacting two tluid phases. In a vertical vessel adapted for the supply and the discharge of uids there are at least two plates one above the other adapted to be moved reciprocatingly in the direction of the longitudinal axis of the vessel. The plates are provided with two types of holes differing in size and may also differ in shape. The area of the smallest holes of the larger type is at least three times larger than the area of the largest holes of the smaller type. The number of holes of the smaller type is at least 65% of the total number of holes in a plate. The position of holes in adjacent plates are different. The plates may be provided on one side with an adjustable or stationary baille.

BACKGROUND OF THE INVENTION (l) Field of the invention The invention relates to a device for the contact of at least two liquid phases, particularly for extracting one liquid from another liquid, for the absorption of gases in liquids and for permitting a reaction between at least two liquid phases.

When carrying out chemical reactions and physical processes on an industrial scale it is often necessary to bring two or more liquid phases into close contact, or to maintain such phase in close contact. Devices suitable for permitting and controlling such processes are therefore equipped with suitable internal built-in devices. Suitable devices are for example stirring devices of various constr-uctions driven by individual electromotors, or partitions and plates in various combinations.

(2) Description of the prior art There is for example a device for countercurrent contact of two incompletely miscible liquids of diierent densities into which one liquid is supplied continuously andl the other discontinuously. The device comprises a plurailty of vertical partitions distributed in space in a horizontal plane, as for example disclosed in U.S. patent specication No. 2,791,537.

A device is also known multistage extraction. This device comprises a plurality of adjacent departments through which liquids ow continuously and countercurrently, as disclosed for example in French patent specication No. 1,328,710.

Another known device consists of a column with sieve type trays arranged above each other. The individual trays are arranged alternately against each other and a free space is left between the upper edge of each sieve type tray and the internal wall of the column, as disclosed for example in German patent specification No. 1,103,299.

Still another known device adapted for mixing and separating comprises a prismatic hollow body with an internal wall against which are arranged rotatably and adjustably impact plates as disclosed in the German patent specification No. 1,159,396.

Many of the known devices are attended with various drawbacks residing for example in the fact that the transflux is impaired due to irregular flow of the two phases in a given section of the device. Another drawback resides in the creation of irregularities, for example in the mutual countercurrent flow of the treated phases which reduces the efciency of the device due to remixing which reduces the mean concentration slope.

Another drawback is connected with the size of particles. Dispersions produced inthe device are very irregular, as shown, for example by R. E. Treybal in Liquid Extraction, McGraw-Hill, New York, 1963.

SUMMARY OF THE IINVENTION It is a general object of the device to improve the known state of art and to suppress or largely eliminate the above mentioned drawbacks.

A more specific object of the invention is a device for the contact of two liquid phases comprising a vertical vessel having the shape of a cylinder with branches for the supply and discharge of liquids. In the vessel there are arranged at least two horizontal plates one above the other. These plates perform the same reciprocating shifting movement in the direction of the longitudinal axis of the vessel and they are provided with holes of two types differing in size.

To achieve this specic object, the area of the smallest holes of the larger dimension is at least three times larger than the area of the largest holes of the smaller type, and the number of holes of the smaller type is at least 65 of the total number in the plate. The position of the holes in each plate diifer from the position of the holes in adjacent plates. Two types of holes with a different shape may be provided in each plate.

The device for carrying out the invention has plates which, on the side to which flows the dispersed phase are provided with a vertical portion which is for example adjustable and which extends at the utmost to %0 of the distance between adjacent plates.

The invention is based on the recognition that in a device of this type it is possible, by means of a reciproeating shifting movement of the plate, to increase the turbulence in the continuous phase and the circulation in drops, and that it is further possible to increase the interphase surface which leads to an increase in eciency.

In the device in accordance with the invention it is possible to achieve an increased interphase surface without the creation of a signicant part of a too fine dispersion which is easily carried along by the continuous phase. The increased interphase surface is produced by a suitable combination of the reciprocating shifting movement and the size of the holes in the plate which permits to achieve sufficiently large drops to prevent them being carried along by the continuous phase, but also suiciently small to produce a large interphase surface.

A device in accordance with the invention permits therefore to operate at large relative phase velocities, for example at a velocity of 2 to 4 cm./sec. and thus to achieve high performances. The vertical partition arranged on the lower or upper edge of the large holes producesduring the intermittently shifting movement of the plate such pressure conditions in its neighbourhood that during part of the oscillation during which the plate moves in the direction opposed to the direction of movement of the dispersed phase, the passage of the dispersed phase through the small holes is increased while its flow Y through the large holes is reduced. The adjustability of direction of stationary partitions. It is desirable for the position of the large holes in adjacent plates to be different with respect to the axis of the vessel to prevent direct passage of the continuous phase over the shortest path.

Until now the only plate known for extraction by means of a liquid in countercurrent was a perforated plate or sieve or grid without overflow in which adjacent holes alternately distributed over the entire area of the immovable plate have different sizes, as disclosed in Czechoslovak patent specification No. 92,282.

The difference between the device in accordance with the disclosure of the mentioned Czechoslovak patent specification and the present invention resides in the fact that a novel and higher effect is achieved by the novel device on the hand in that in the plate there are arranged large holes of non-uniform size in a certain mutual relationship preferably arranged irregularly, on the other hand in that the plate is set into a reciprocating shifting movement, or into an oscillatory movement. This produces forces of inertia which accelerate the liquid phase when it passes through a hole in the plate in an alternate direction. Thus, in the part of the shift or oscillation in which this force is operative in a direction coinciding with the lifting force, there are discharged from the hole drops of the dispersed phase the velocity of which may even exceed the velocity of fall of the drops.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be best understood from the following specication to be read in conjunction with the accompanying drawings illustrating preferred embodiments which, however, do not exhaust the entire scope thereof.

In the drawings:

PIG. l is an axial section through a vertically arranged cylindrical reactor with two plates;

FIGS. 2 and 3 show another type of plate;

FIG. 4 illustrates a plate with a perpendicular partition having the shape of a cylinder;

FIG. illustrates a plate which is provided on its lower edge with a packing member and a holding ring; and

FIGS. 6 and 7 illustrate a plate with a perpendicularly arranged partition adjustable in the direction of the vertical axis.

Referring now more particularly to FIG. l which represents a reactor in an axial section, it can be seen that in the envelope 1 there is arranged an inlet hole 2 for a specifically heavier phase. The inlet hole 2 is arranged above the outlet hole 4 of the same phase. The inlet hole 3 of a specifically lighter phase is arranged under the outlet hole 5 of this phase. On a vertically arranged shaft 6 which passes through a footstep bearing 7 there are attached horizontal plates 8 provided with large holes 9 and small holes 10.

FIG. 2 shows another type of plate 8 in which the large hole 9 which is arranged in one part of the plate has the shape of a sector of a circle. In the remaining part of the plate 8 there are arranged small holes 10.

FIG. 3 shows a plate 8 in which both the large hole 9 and the small holes 10 have circular shapes. The large hole 9 in this embodiment is provided on its lower part with a vertical partition 11 of cylindrical shape.

FIG. 4 illustrates a plate 8 in which both the large hole 9 and the small holes 10 are of circular shapes. The plate 8 carries a vertical partition 12 on its circumference which rests against the inner wall of the reactor envelope 1. This partition 12 extends below the lower plate surface. The large hole 9 is provided on its lower side with a vertical partition 11 having the shape of a cylindrical envelope.

FIG. 5 represents a tray with large and small holes which is provided on its lower side with a resilient packing piece 13 attached by means of a holding ring 14.

FIG. 6 shows a tray with a vertical partition 11 with two elongated holes 15 in a direction parallel with the vertical axis of the vessel. Through these holes 15 there pass screws 16 permitting to adjust the position of the partition with respect to the tray. As shown in PIG. 6 the screws are set to their lower position in the holes 1S and in FIG. 7 they are set to the central position in the holes 15.

What is claimed is:

1. An apparatus for contacting two fiuid phases with each other comprising, in combination, a vessel having a vertical axis and being provided in the region of the top and the bottom thereof with fluid inlet and outlet means; a reciprocating shaft extending in the direction of said axis through and beyond one end of said vessel; at least two substantially horizontal plates spaced vertically from each other extending transversely through said vessel and being fixed to said shaft for reciprocation therewith, each of said plates being provided with two types of holes respectively having cross-sections of different size, the smallest hole of the larger type having a cross-section at least three times as large as the largest hole of the smaller type, the number of holes of the smaller type in each plate amount to at least 65% of the total number of holes in said plate, the holes in each plate being arranged in groups of each type, each group of the holes of the larger type in each plate being substantially and circumferentially displaced with regard to each group of the holes of the larger type of the adjacent plate and each group of the holes of the smaller type in each plate being substantially and circumferentially displaced with regard to each group of the holes of the smaller type of the adjacent plate.

2. An apparatus as defined in claim 1, in which said holes of two types have also different shapes.

3. An apparatus as defined in claim 1, wherein each of said plates is provided along the outer periphery thereof with a vertical bafiie extending at the most to 5%[0 of the distance between adjacent plates, said baie projecting only to one side of the respective plate towards the plate adjacent thereto.

4. An apparatus as defined in claim 1, wherein each plate is provided with only one hole of the larger type, said one hole in one plate being located to one side of said shaft and said one hole in the adjacent plate being located at the diametrically opposite side of said shaft.

5. An apparatus as defined in claim 4, wherein said one hole extends from the periphery of the respective plate into the latter.

6. An apparatus as defined in claim 1, wherein said vessel is of cylindrical shape and wherein said shaft is coaxially arranged in said vessel.

7. An apparatus as defined in claim 6, wherein said holes of two types have also different shapes.

8. An apparatus as defined in claim 1, in which a hole of the larger type is provided with a vertical bafiie.

9. An apparatus as defined in claim 8, wherein said vertical baflie is adjustable in vertical direction.

10. An apparatus as defined in claim 8, in which each of said plates are provided along the outer periphery thereof with a vertical baffle extending at the most to W10 of the distance between adjacent plates, the vertical baffle at the hole of the larger type and the vertical bafiie at the periphery of the respective plate extending to the same side of the respective plate.

11. An apparatus for contacting two Huid phases with each other comprising, in combination, a vessel having a vertical axis and being provided in the region of the `top and the bottom thereof with fluid inlet and outlet means; a reciprocating shaft extending in the direction of said axis through and beyond one-end of said vessel; at least two substantially horizontal plates spaced vertically from each other extending transversely through said vessel and being fixed to said shaft for reciprocation therewith, each of said plates being provided with two types of holes respectively having cross-sections of different size, the smallest hole of the larger type having a cross-section at least three times as large as the largest hole of the smaller type, the number of holes of the smaller type in each plate amount to at least 65% of the total number of holes in said plate, the holes in each plate being arranged in groups of each type, each group of the holes of the larger type in each plate being located to one side of said shaft and each group of the holes of the larger typeof the adjacent plate being located at the side opposite said one side of said shaft and each group of the holes of the smaller type in each plate being located to one other side of said shaft and each group of the holes of the smaller type of the adjacent plate being located at the side opposite said one other side of said shaft.

References Cited UNITED STATES PATENTS 2,011,186 8/1935 Van Dijct 23-267 3,318,668 5/1967 Ziehl 23-270 Re. 21,725 2/1941 Harrington 23-310 2,632,720 3/ 1953 Perry 23--270X 6 2,647,855 8/1953 Grunewald 196-1451 2,837,408 6/1958 SakOWski 23-270.5X 2,924,441 2/1960 Osborne 23a-270.52( 2,985,637 3/1961 Anselm 23-267X 3,273,872 9/1966 Eckert 23--270.5X 3,278,275 10/1966 Barnard 23--270X FOREIGN PATENTS 876,070 8/ 1961 Great Britain 23-267 OTHER REFERENCES Goldberger et al., Industrial and Engineering Chemistry, Vol. 51, No. 5, May 1959, pp. 641 thru 644.

WILBUR L. BASCOMB, JR., Primary Examiner S. I. EMERY, Assistant Examiner U.S. Cl. X.R. 

